JP2009090641A - Anticlouding cover and cover for meter using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anticlouding cover having high water affinity and excellent durability in high-temperature and high-humidity surroundings, especially a cover for meters. <P>SOLUTION: The anticlouding cover is coated with a hydrophilic composition on at least one side of the substrate, and the surface of the coating layer has a contact angle of ≤15° before and after 500-hour immersion in water at 30°C and a center line average roughness Ra of 1.0-5.0 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to the antifogging cover particularly useful as a meter cover.

  Various meters are attached to automobiles, motorcycles, agricultural machinery, heavy construction machinery, ships, factory equipment, or utility facilities such as gas, water, and electricity. Usually, a cover made of transparent glass or resin is used. However, in the meter cover, moisture often precipitates due to changes in temperature and humidity conditions or becomes cloudy, or transparency decreases due to dirt, resulting in a decrease in the visibility of the meter display, and sometimes it is difficult to see. Furthermore, meters exposed outdoors such as agricultural machinery, heavy construction machinery, factory equipment, and utility facilities are in harsh environments where they are exposed not only to sunlight, wind and rain, but also to dust. When it rains and the panel surface of the meter cover cools, water droplets are generated inside the panel and the visibility of the meter is significantly reduced. Even after the water droplets evaporate and disappear, water residue remains on the inner surface of the panel. . And this residue increased the adhesion amount with time, became the cause of deteriorating the beauty as well as the visibility.

  Therefore, conventionally, in order to suppress fogging due to changes in temperature and humidity conditions, it has been proposed to antifogging the meter cover. Many of the conventionally proposed antifogging treatments for meter covers are to coat the surface with a synthetic resin antifogging agent. However, synthetic resin antifogging agents are not sufficiently chemically and thermally stable, may cause deterioration with time, and may limit usage temperature conditions. Moreover, it cannot be said that the anti-fogging property is sufficient, and further, the anti-fogging property itself becomes dirty, causing the visibility of the meter to deteriorate. Therefore, it cannot be said that this synthetic resin antifogging agent is particularly sufficient as an antifogging treating agent for a meter attached to the outside as described above.

  Further, in recent years, a meter cover having a film containing a photocatalyst typified by titanium oxide has been developed in place of the above synthetic resin antifogging agent. In this photocatalyst, electrons in the valence band are excited by irradiation of light (ultraviolet rays) to generate holes or conduction electrons, and impart polarity to the surface of the film to develop hydrophilicity. And, by the action of this photocatalyst, the meter cover is imparted with a high hydrophilicity of 10 ° or less as a contact angle with water, and the adhesion of water droplets is extremely effectively prevented. Further, once imparted hydrophilicity has an advantage that it can be maintained well over a long period of time even under weak illumination such as indoors, and even in a dark place. Regarding such a photocatalytic film, see, for example, JP-A-9-57912, JP-A-9-59041, JP-A-9-59042, JP-A-9-227160, JP-A-9-224793, etc. can do.

For example, Patent Document 1 discloses an antifogging agent characterized by comprising polyvinyl alcohol, methyl vinyl ether / maleic anhydride copolymer, and water as main components.
Patent Document 2 discloses an antifogging agent characterized by being formed by condensation polymerization by subjecting an organic substance having a hydroxyl group, a metal organic compound, and heat treatment thereof.
Patent Document 3 discloses an antifogging / antifouling meter cover characterized in that a photocatalytic film is formed on a resin substrate by binding a crystalline titanium oxide fine powder with a binder made of amorphous titanium oxide. ing.
Patent Document 4 discloses a hydrophilic composition containing a specific hydrophilic polymer and an alkoxide compound of an element selected from Si, Ti, Zr, and Al.
However, although the techniques of Patent Documents 1 and 2 are anti-fogging agents using polyvinyl alcohol, sufficient hydrophilicity cannot be obtained, or the polymer is dissolved by dewed water, which is satisfactory in hydrophilic sustainability. It wasn't going.
In the technique of Patent Document 3, a sufficient effect cannot be obtained at night when no light (ultraviolet rays) is applied. In addition, there is a drawback that the vehicle is parked at night and the visibility is deteriorated due to condensation in early morning and night dew.
In order to achieve the above-mentioned problems, the anti-fogging and anti-fogging properties of the hydrophilic surface with a cross-linked structure by hydrolyzing and condensation-polymerizing the hydrophilic polymer and the alkoxide are focused on the characteristics of the sol-gel organic-inorganic hybrid film. It has been found that it exhibits fouling and has good wear resistance (see Patent Document 4). However, further improvement is demanded regarding durability in a hot and humid environment.
Japanese Patent Laid-Open No. 9-235544 JP-A-10-212471 JP 11-189109 A JP 2007-138105 A

  An object of the present invention is to provide an antifogging cover having high hydrophilicity and excellent durability in a high temperature and high humidity environment, particularly an antifogging cover for a meter.

The above problems have been solved by the following means.
1. An anti-fogging cover in which a hydrophilic composition is coated on at least one surface of a substrate. The surface of the coating layer has a contact angle with water both before and after being immersed in water at 30 ° C. for 500 hours. An anti-fogging cover characterized by being 15 ° or less and having a center line average roughness Ra of 1.0 nm to 5.0 nm.
2. 2. The antifogging cover as described in 1 above, wherein a contact angle with water is 10 ° or less before and after immersion in water at 30 ° C. for 500 hours.
3. 3. The antifogging cover as described in 1 or 2 above, wherein the substrate is made of any one of glass, acrylic resin and polycarbonate resin.
4). The difference between the refractive index of the coating layer and the refractive index of the substrate is 0.5% to 30.0% of the refractive index of the coating layer. Haze cover.
5). 5. The antifogging cover as described in any one of 1 to 4 above, wherein the hydrophilic composition contains a polymer having an alkoxysilyl group in the molecule.
6). 6. The antifogging cover as described in 5 above, wherein the polymer having an alkoxysilyl group in the molecule has a structure represented by the following general formula (II).

In the general formula (II), R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group, X represents a group represented by the following general formula (a), L ² and L ³ each independently represents a single bond or a linking group, and Y represents —NHCOR, —NHCO ₂ R, —NHCONR ₂ , —CONH ₂ , —NR ₂ , —CONR ₂ , —OCONR ₂ , —COR, —OH, _{-OR, -CO 2 M, -CO 2} R, -SO 3 M, -OSO 3 M, -SO 2 R, -NHSO 2 R, -SO 2 NR 2, -PO 3 M, -OPO 3 M, - (CH ₂ CH ₂ O) _n H, — (CH ₂ CH ₂ O) _n CH ₃ or —NR ₃ Z ¹ , wherein R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, When there are a plurality, they may be the same or different, and M is a hydrogen atom, Kill group, an alkali metal, alkaline earth metal or an onium, n represents an integer, Z ¹ represents a halogen ion.
Formula (a): —Si (R ¹⁰² ) _a (OR ¹⁰¹ ) _3-a
(In General Formula (a), R ¹⁰¹ represents a hydrogen atom or an alkyl group, R ¹⁰² represents a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group, an aryl group, and an aralkyl group, and a represents 0-2. (In the case where a plurality of R ¹⁰¹ or R ¹⁰² are present, they may be the same as or different from each other.)
7). 7. The antifogging cover as described in any one of 1 to 6 above, wherein the hydrophilic composition contains an alkoxide compound of any element selected from Si, Ti, Zr, and Al.
8). The surface of the coating layer has a contact angle with water of 5 ° or more and 15 ° or less both before and after being immersed in water at 30 ° C. for 500 hours. Antifogging cover as described.
9. 9. A meter cover, wherein the antifogging cover according to any one of 1 to 8 is used for a meter.

  The anti-fogging cover of the present invention has a water contact angle of 15 ° or less before and after being immersed in water at 30 ° C. for 500 hours, and has an unprecedented high hydrophilicity. For this reason, when the anti-fogging cover is used as a meter cover, even if water condensed due to changes in temperature and humidity conditions adheres as a water droplet, the water droplet instantly spreads out, so it does not cloud and has excellent visibility. . Furthermore, since the hydrophilicity can be exhibited with a thinner layer than in the prior art, there is an effect that the transparency of the substrate itself is not impaired. Moreover, even after being immersed in water for a long period of time, the contact angle of water is 15 ° or less, high hydrophilicity can be maintained for a long period of time, and durability is excellent.

The present invention is described in detail below.
The antifogging cover of the present invention is formed by coating a hydrophilic composition on at least one surface of a substrate.
Preferably, the hydrophilic composition has a hydrophilic polymer chain and is formed by hydrolysis and polycondensation of an alkoxide (also referred to as a metal alkoxide) of an element selected from Si, Ti, Zr, and Al. A coating having a crosslinked structure (also referred to as a hydrophilic film, a hydrophilic layer, or a hydrophilic layer) is formed. The hydrophilic layer having such a crosslinked structure includes a metal alkoxide compound described in detail later and a hydrophilic property. It can be suitably formed using a compound having a hydrophilic functional group capable of forming a graft chain and an appropriate catalyst. Among metal alkoxides, Si alkoxides are preferable from the viewpoint of reactivity and availability, and specifically, compounds used for silane coupling agents can be suitably used.

  In the present invention, the above-described crosslinked structure formed by hydrolysis and polycondensation of the metal alkoxide is hereinafter appropriately referred to as a sol-gel crosslinked structure. Below, each component contained in the hydrophilic coating liquid composition for forming the hydrophilic layer which is this preferable aspect is demonstrated.

[Hydrophilic polymer]
The main chain structure of the hydrophilic polymer is not particularly limited. Preferred main chain structures include acrylic resin, methacrylic resin, polyvinyl acetal resin, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, polystyrene resin, novolac type phenol resin, polyester resin, synthetic rubber, natural rubber, etc. An acrylic resin and a methacrylic resin are particularly preferable. The hydrophilic polymer may be a copolymer.

  The hydrophilic group is preferably a carboxyl group, an alkali metal salt of a carboxyl group, a sulfonic acid group, an alkali metal salt of a sulfonic acid group, a hydroxyl group, an amide group, a carbamoyl group, a sulfonamide group, a sulfamoyl group, or a functional group. Can be mentioned. These groups may be present at any position in the polymer. A polymer structure in which a plurality of polymers are bonded directly from a polymer main chain or via a linking group, or bonded to a polymer side chain or a graft side chain, is preferred.

  Further, the hydrophilic polymer used in the present invention is preferably a polymer having a metal alkoxide and a group that forms a bond by the action of a catalyst or the like. Examples of the group that forms a bond with the metal alkoxide compound by the action of a catalyst include an alkoxysilyl group, a carboxyl group, an alkali metal salt of a carboxy group, a carboxylic anhydride group, an amino group, a hydroxy group, an epoxy group, a methylol group, a mercapto group, Examples thereof include reactive groups such as isocyanate groups, block isocyanate groups, alkoxytitanate groups, alkoxyaluminate groups, alkoxyzirconate groups, ethylenically unsaturated groups, ester groups, and tetrazole groups.

  The polymer structure having a hydrophilic group and a group that forms a bond with a metal alkoxide compound by the action of a catalyst or the like includes an ethylenically unsaturated group (for example, an acrylate group, a methacrylate group, an itaconic acid group, a crotonic acid group, a cinnamic acid group). Styrene group, vinyl group, allyl group, vinyl ether group, vinyl ester group, etc.), polymer obtained by vinyl polymerization, polycondensation polymer such as polyester, polyamide, polyamic acid, etc., addition polymer such as polyurethane, etc. Preferred examples include natural cyclic polymer structures such as cellulose, amylose and chitosan. A polymer having a hydrolyzable silyl group, particularly an alkoxysilyl group in the molecule is preferred.

A hydrolyzable silyl group such as an alkoxysilyl group is a group that reacts with water to produce silanol (Si—OH), and is preferably represented by the following general formula (a).
Formula (a): —Si (R ¹⁰² ) _a (OR ¹⁰¹ ) _3-a
In general formula (a), R ¹⁰¹ is a hydrogen atom or an alkyl group, R ¹⁰² is a monovalent hydrocarbon group selected from a hydrogen atom or an alkyl group, an aryl group and an aralkyl group, and a is an integer of 0 to 2. . When a plurality of R ¹⁰¹ or R ¹⁰² are present, they may be the same as or different from each other.

When R ¹⁰¹ represents an alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and specifically, a methyl group, an ethyl group (that is, OR ¹⁰¹ as a methoxy group, an ethoxy group) and the like are preferable. When R ¹⁰² represents an alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, a hexyl group, or the like is preferable, and when R ¹⁰² represents an aryl group, an aryl group having 6 to 25 carbon atoms is preferable. Group, specifically a phenyl group, and the like are preferable. When an aralkyl group is represented, an aralkyl group having 7 to 12 carbon atoms is preferable, and a styryl group and the like are specifically preferable.

The alkoxysilyl group is preferably an alkoxysilyl group bonded to a carbon atom.
There may be a case where one or a plurality of alkoxysilyl groups are present at the terminal of the polymer main chain or a case where one or a plurality of alkoxysilyl groups are present in the side chain. When two or more alkoxysilyl groups are contained, the two or more alkoxysilyl groups may be the same as or different from each other.

  The alkoxysilyl group can form a chemical bond by reacting with a hydrolysis or polycondensate of an alkoxide (also referred to as a metal alkoxide) containing an element selected from Si, Ti, Zr, and Al described later. Moreover, alkoxysilyl groups may form a chemical bond. The hydrophilic polymer is preferably water-soluble, and preferably becomes water-insoluble by reacting with a hydrolysis or polycondensate of a metal alkoxide. The chemical bond in this case includes a covalent bond, an ionic bond, a coordination bond, and a hydrogen bond in the same manner as usual. The chemical bond is preferably a covalent bond.

  A linking group is preferably interposed between the repeating unit containing a hydrophilic group and the alkoxysilyl group, or between the repeating unit containing a hydrophilic group and the main chain.

  The hydrophilic polymer is preferably a hydrophilic polymer including a structure represented by the following general formula (I) or the following general formula (II).

In the general formulas (I) and (II), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group, and X represents the above general formula (a) A, L ¹ , L ² , and L ³ each independently represent a single bond or a linking group, and Y represents —NHCOR, —CONH ₂ , —NR ₂ , —CONR ₂ , — COR, —OH, —CO ₂ M, —SO ₃ M, —PO ₃ M, —OPO ₃ M, — (CH ₂ CH ₂ O) _n H, — (CH ₂ CH ₂ O) _n CH ₃ or NR ₃ Represents Z ¹ , wherein R represents an alkyl group, an aryl group, or an aralkyl group, and when there are a plurality thereof, they may be the same as or different from each other, and M represents a hydrogen atom, an alkali metal, an alkaline earth metal, or an onium. , N represents an integer, and Z ¹ represents a halogen ion.

  Since many hydrolyzable silyl groups per molecule can be introduced, a hydrophilic polymer having a structure represented by the general formula (II) is particularly preferable.

(Hydrophilic polymer having a structure represented by the general formula (I))
Hydrophilic polymers having a structure represented by the general formula (I) include, for example, chain transfer agents (described in radical polymerization handbooks (NTS, Mikiharu Tsunoike, Takeshi Endo)) and Iniferter (Macromolecules 1986, 19, p287). -(Described in (Otsu)) in the presence of a hydrophilic monomer (eg, acrylamide, acrylic acid, potassium salt of 3-sulfopropyl methacrylate) by radical polymerization. Examples of chain transfer agents include 3-mercaptopropionic acid, 2-aminoethanethiol hydrochloride, 3-mercaptopropanol, 2-hydroxyethyl disulfide, 3-mercaptopropyltrimethoxysilane. Alternatively, a hydrophilic monomer (eg, acrylamide) may be radically polymerized using a radical polymerization initiator having a reactive group without using a chain transfer agent.

The hydrophilic polymer having the structure represented by the general formula (I) is a hydrophilic polymer having a reactive group at the terminal. In the general formula (I), R ¹ and R ² each independently represents a hydrogen atom or a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group and an aryl group, and a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms is preferable. Specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group and the like. R ¹ and R ² are preferably a hydrogen atom, a methyl group or an ethyl group from the viewpoints of effects and availability.

  These hydrocarbon groups may further have a substituent. When the alkyl group has a substituent, the substituted alkyl group is composed of a bond between the substituent and the alkylene group, and a monovalent nonmetallic atomic group excluding hydrogen is used as the substituent. Preferred examples include halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, amino groups, N-alkylamino groups, N, N-dialkyls. Amino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfamo Group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkyl phosphono group, diaryl phosphono group, monoalkyl phosphono group, alkyl phosphonate group, monoaryl phosphono group, aryl phosphine group Examples include an onato group, a phosphonooxy group, a phosphonateoxy group, an aryl group, and an alkenyl group.

  On the other hand, examples of the alkylene group in the substituted alkyl group include a divalent organic residue obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 8 carbon atoms. Can include linear alkylene groups having 1 to 12 carbon atoms, branched chains having 3 to 12 carbon atoms, and cyclic alkylene groups having 5 to 10 carbon atoms. Preferable specific examples of the substituted alkyl group obtained by combining the substituent and the alkylene group include a hydroxymethyl group, a chloromethyl group, a bromomethyl group, a 2-chloroethyl group, a trifluoromethyl group, a methoxymethyl group, and a methoxyethoxy group. Ethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl Group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxyethyl group, 2-oxypropyl group, carboxypropyl group, methoxycarbonyl group Group, allyloxycarbonyl butyl group,

Chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group , Sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phos Phonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphos Onatohexyl group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1 -Propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group and the like can be mentioned.

  Of these, a hydroxymethyl group is preferred from the viewpoint of hydrophilicity.

A and L ^{1 each} represents a single bond or an organic linking group. Here, when A and L ¹ represent an organic linking group, A and L ¹ represent a polyvalent linking group composed of a non-metallic atom, including 0 to 60 carbon atoms, 0 to 10 carbon atoms. It consists of nitrogen atoms, 0 to 50 oxygen atoms, 0 to 100 hydrogen atoms, and 0 to 20 sulfur atoms. Specifically, it is preferably selected from -N <, an aliphatic group, an aromatic group, a heterocyclic group, and combinations thereof, -O-, -S-, -CO-, -NH-, or A combination containing —O— or —S— or —CO— or —NH— is preferably a divalent linking group.
More specific examples of the linking group include the following structural units or those formed by combining them.

A and L ¹ are more preferably —CH ₂ CH ₂ CH ₂ S—, —CH ₂ S—, —CONHCH (CH ₃ ) CH ₂ —, —CONH—, —CO—, —CO ₂ —, — CH ₂ - is.

In general formula (I), Y represents —NHCOR, —CONH ₂ , —N (R) ₂ , —CON (R) ₂ , —COR, —OH, —CO ₂ M, —SO ₃ M, —PO ₃ M , —OPO ₃ M, — (CH ₂ CH ₂ O) _n H, — (CH ₂ CH ₂ O) _n CH ₃ or N (R) ₃ Z ¹ , where R is preferably carbon number 1 Represents a straight-chain, branched or cyclic alkyl group, aryl group or aralkyl group of -18, which may be the same or different from each other, and M represents a hydrogen atom, an alkali metal, an alkaline earth metal or onium. N represents an integer, and Z ¹ represents a halogen ion. Moreover, when it has several R like -CON (R) ₂ , R may couple | bond together and it may form the ring and the formed ring is oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be a heterocycle containing a heteroatom. R may further have a substituent, and examples of the substituent that can be introduced here include the same substituents that can be introduced when R ¹ and R ² are alkyl groups. it can.

  Specific examples of R include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, isopropyl, isobutyl, s-butyl, t-butyl, and isopentyl. Preferred examples include a group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group and the like. Examples of M include a hydrogen atom; an alkali metal such as lithium, sodium and potassium; an alkaline earth metal such as calcium and barium; or an onium such as ammonium, iodonium and sulfonium.

The Y, _{specifically, -NHCOCH 3, -CONH 2, -CON} (CH 3) 2, -COOH, -SO 3 - NMe 4 +, -SO 3 - K +, - (CH 2 CH 2 O _N H, morpholyl group and the like are preferable. More _{preferably, -NHCOCH 3, -CONH 2, -CON} (CH 3) 2, -SO 3 - K +, - (CH 2 CH 2 O) n H, is.

  n preferably represents an integer of 1 to 100.

  The hydrophilic polymer having a structure represented by the general formula (I) includes a radical polymerizable monomer represented by the following general formula (i) and a chain transfer ability in the radical polymerization represented by the following general formula (ii). It can be synthesized by radical polymerization using a silane coupling agent having Since the silane coupling agent (ii) has chain transfer ability, it is possible to synthesize a polymer in which a silane coupling group is introduced at the end of the polymer main chain in radical polymerization.

In the above formulas (i) and (ii), A, R ^{1 to} R ² , L ¹ , X and Y have the same meanings as those in the above general formula (I). These compounds are commercially available and can also be easily synthesized. The radically polymerizable monomer represented by the general formula (i) has a hydrophilic group Y, and this monomer becomes one structural unit in the hydrophilic polymer.

  The hydrophilic polymer containing the structure represented by the general formula (I) may be a copolymer with another monomer. Examples of other monomers used include acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, maleic imide, etc. These known monomers are also included. By copolymerizing such monomers, various physical properties such as film forming property, film strength, hydrophilicity, hydrophobicity, solubility, reactivity, and stability can be improved.

  Specific examples of acrylic esters include methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec- or t-) butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, Dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, chloro Benzyl acrylate, hydroxybenzyl acrylate, hydroxyphenethyl acrylate, dihydroxyphene Chill acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate, 2- (hydroxyphenyl carbonyloxy) ethyl acrylate.

  Specific examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, (n- or i-) propyl methacrylate, (n-, i-, sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, benzyl methacrylate, methoxybenzyl methacrylate, chloro Benzyl methacrylate, hydroxybenzyl methacrylate, hydroxy E phenethyl methacrylate, dihydroxyphenethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 2- (hydroxyphenyl carbonyloxy) ethyl methacrylate.

  Specific examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, and N-tolylacrylamide. N- (hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl) acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-N-phenylacrylamide , N-hydroxyethyl-N-methylacrylamide and the like.

  Specific examples of methacrylamides include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide, N-benzylmethacrylamide, N-hydroxyethylmethacrylamide, N -Phenylmethacrylamide, N-tolylmethacrylamide, N- (hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N- (tolylsulfonyl) methacrylamide, N , N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

Specific examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate and the like.
Specific examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, propyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, dimethoxy styrene. Chlorostyrene, dichlorostyrene, bromostyrene, iodostyrene, fluorostyrene, carboxystyrene and the like.

  The mass average molecular weight of the hydrophilic polymer containing the structure represented by the general formula (I) is preferably 1,000 to 1,000,000, more preferably 1,000 to 500,000, and 1,000 to 200,000. 000 is most preferred.

  Specific examples of the hydrophilic polymer having a structure represented by the general formula (I) that can be suitably used in the present invention are shown below, but the present invention is not limited thereto.

(Hydrophilic polymer having a structure represented by the general formula (II))
In the general formula (II), R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group, and specific examples and preferred ranges thereof are those represented by R ^{1 in the} general formula (I). , R ² . L ² and L ³ each independently represents a single bond or a linking group, and specific examples and preferred ranges are the same as those for L ^{1 in the} above general formula (I). The definitions of Y and X are the same as those in formula (I), and specific examples and preferred ranges are also the same.

In the general formula (II), L ³ has a single bond or one or more structures selected from the group consisting of —CONH—, —NHCONH—, —OCONH—, —SO ₂ NH—, and —SO ₃ —. A linking group is preferred.

Each compound for synthesizing the hydrophilic polymer having the structure represented by the general formula (II) is commercially available or can be easily synthesized.
Any conventionally known method can be used as the radical polymerization method for synthesizing the hydrophilic polymer having the structure represented by the general formula (II).
Specifically, general radical polymerization methods include, for example, New Polymer Experiments 3 (1996, Kyoritsu Shuppan), Polymer Synthesis and Reaction 1 (Polymer Society of Japan, 1992, Kyoritsu Shuppan), New Experiment Chemistry Lecture 19 (1978, Maruzen), Polymer Chemistry (I) (Edited by The Chemical Society of Japan, 1996, Maruzen), Synthetic Polymer Chemistry (Materials Engineering Lecture, 1995, Tokyo Denki University Press) These can be applied.

  The hydrophilic polymer having a structure represented by the general formula (II) may be a copolymer with another monomer as described later.

  The mass average molecular weight of the polymer containing the structure represented by the general formula (II) is preferably 1,000 to 1,000,000, more preferably 1,000 to 500,000, and 1,000 to 200,000. Most preferred.

The copolymerization ratio of the hydrophilic polymer containing the structure represented by the general formula (II) is such that the molar ratio (m ₂ ) of the structural unit containing Y and the molar ratio (n ₂ ) of the structural unit containing X are: _{m 2 / n 2 = 30 /} 70~99 / 1 range is preferred, more preferably _{m 2 / n 2 = 40 /} 60~98 / 2, m 2 / n 2 = 50 / 50~97 / 3 is the most preferable. If m ₂ / n ₂ is 30/70 or more, the hydrophilicity is not insufficient. On the other hand, if m ₂ / n ₂ is 99/1 or less, the reactive group amount is sufficient and sufficient curing is achieved. As a result, the film strength is sufficient.
The copolymerization ratio can be measured with a nuclear magnetic resonance apparatus (NMR) or a calibration curve prepared with a standard substance and measured with an infrared spectrophotometer.

   Specific examples of the hydrophilic polymer having the structure represented by the general formula (II) are shown below together with the mass average molecular weight (M.W.), but the present invention is not limited thereto. In addition, the polymer of the specific example shown below means that it is a random copolymer in which each structural unit described is contained in the described molar ratio.

  The hydrophilic polymer having the structure represented by the general formula (II) may be a copolymer with another monomer. Examples of other monomers used include acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, maleic imide, etc. These known monomers are also included. These specific examples are the same as those described above. By copolymerizing such monomers, various physical properties such as film forming property, film strength, hydrophilicity, hydrophobicity, solubility, reactivity, and stability can be improved.

  The ratio of these other monomers needs to be an amount sufficient to improve various physical properties, but it has sufficient functions as a hydrophilic film and has the advantages of the structure represented by the general formula (II). In order to obtain, it is preferred that the proportion is not too large. Therefore, the total proportion of the structures derived from the other monomers in the hydrophilic polymer is preferably 80% by mass or less, and more preferably 50% by mass or less.

  The hydrophilic composition in this invention may contain the hydrophilic polymer containing the structure represented by general formula (I) or (II) individually or in 2 types or more.

  Examples of hydrophilic polymers other than the above include polyacrylic acids, polymethacrylic acids, polyacrylamides, and sulfonic acid esters thereof having polar groups such as —OH, —COOH, and amino groups. Specific examples thereof include the following.

  The hydrophilic polymer according to the present invention is contained in the range of 20% by mass to 100% by mass with respect to the solid content (nonvolatile component) of the hydrophilic composition of the present invention from the viewpoint of curability and hydrophilicity. It is preferable. More preferably, it is 50 mass%-100 mass%. Here, the non-volatile component refers to a component excluding a volatile solvent.

  The preferred mass ratio when the hydrophilic composition contains a hydrophilic polymer containing a structure represented by the general formula (I) and a hydrophilic polymer containing a structure represented by the general formula (II) is (general The hydrophilic polymer including the structure represented by the formula (I) / the hydrophilic polymer including the structure represented by the general formula (II) is 50/50 to 5/95.

  The hydrophilic polymer having a structure represented by the general formula (I) or (II) forms a crosslinked film in a state where it is mixed with a hydrolysis and polycondensate of a metal alkoxide. The hydrophilic polymer, which is an organic component, is involved in the film strength and film flexibility. In particular, the viscosity measured at 20 ° C. of a 5% aqueous solution of the hydrophilic polymer is 0.1 to 100 mPa · s, preferably When it is in the range of 0.5 to 70 mPa · s, more preferably 1 to 50 mPa · s, good film properties are provided. The viscosity can be measured with an E-type viscometer (trade name: RE80L, manufactured by Tokyo Keiki Co., Ltd.).

Solvents used to synthesize hydrophilic polymers include tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, propanol, acetonitrile, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol Dimethyl ether, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, toluene, ethyl acetate, methyl lactate, methyl lactate, dimethyl Examples thereof include sulfoxide and water. These solvents are used alone or in combination of two or more.
As the radical polymerization initiator used for synthesizing the hydrophilic polymer, known compounds such as an azo initiator, a peroxide initiator, and a redox initiator can be used.

[Metal alkoxide compound selected from Si, Ti, Zr, and Al]
The metal alkoxide compound used in the present invention is a hydrolyzable polymerizable compound having a functional group capable of being hydrolyzed and polycondensed in its structure and serving as a crosslinking agent, and metal alkoxides are polycondensed with each other. As a result, a strong cross-linked film having a cross-linked structure is formed, and the hydrophilic polymer is also chemically bonded. The metal alkoxide can be represented by general formula (I-1) and general formula (I-2), in which R ⁸ represents a hydrogen atom, an alkyl group or an aryl group, and R ⁹ represents an alkyl group or an aryl group. Z represents Si, Ti or Zr, and m represents an integer of 0-2. The number of carbon atoms when R ⁸ and R ⁹ represent an alkyl group is preferably 1 to 4. The alkyl group or aryl group may have a substituent, and examples of the substituent that can be introduced include a halogen atom, an amino group, and a mercapto group. This compound is a low molecular compound and preferably has a molecular weight of 2000 or less.

^{_{(R 8) m -Z- (OR}} 9) 4-m (I-1)
Al- (OR ⁹ ) ₃ (I-2)

  Although the specific example of the hydrolysable compound represented by general formula (I-1) and general formula (I-2) below is given, this invention is not limited to this. When Z is Si, that is, the hydrolyzable compound containing silicon includes, for example, trimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, γ- Examples include chloropropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, and the like. Among these, particularly preferred are trimethoxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane and the like.

When Z is Ti, i.e., including titanium, for example, trimethoxy titanate, tetramethoxy titanate, triethoxy titanate, tetraethoxy titanate, tetrapropoxy titanate, chlorotrimethoxy titanate, chlorotriethoxy titanate, ethyl Examples include trimethoxy titanate, methyl triethoxy titanate, ethyl triethoxy titanate, diethyl diethoxy titanate, phenyl trimethoxy titanate, and phenyl triethoxy titanate.
When Z is Zr, that is, the one containing zirconium can include, for example, zirconates corresponding to the compounds exemplified as those containing titanium.
Further, when the central metal is Al, that is, examples of those containing aluminum in the hydrolyzable compound include trimethoxy aluminate, triethoxy aluminate, tripropoxy aluminate, triisopropoxy aluminate, and the like. be able to.
The metal alkoxide compound selected from Si, Ti, Zr, and Al is preferably contained in the hydrophilic composition in an amount of 10 to 80% by mass, and more preferably 20 to 50% by mass.

〔catalyst〕
The metal complex catalyst that can be used in the formation of the hydrophilic layer of the present invention promotes hydrolysis and polycondensation of a metal alkoxide compound selected from Si, Ti, Zr, and Al, and causes a bond with a hydrophilic polymer. Can do. Particularly preferred metal complex catalysts include metal elements selected from groups 2A, 3B, 4A and 5A of the periodic table and β-diketones, ketoesters, hydroxycarboxylic acids or esters thereof, amino alcohols, and enolic active hydrogen compounds. It is a metal complex composed of a selected oxo or hydroxy oxygen-containing compound.
Among the constituent metal elements, 2A group elements such as Mg, Ca, Sr and Ba, 3B group elements such as Al and Ga, 4A group elements such as Ti and Zr, and 5A group elements such as Nb and Ta are preferable. Each forms a complex with an excellent catalytic effect. Of these, complexes obtained from Zr, Al and Ti are excellent and preferred.

  In the present invention, the oxo- or hydroxy-oxygen-containing compound constituting the ligand of the metal complex is a β-diketone such as acetylacetone (2,4-pentanedione) or 2,4-heptanedione, methyl acetoacetate, acetoacetic acid Ketoesters such as ethyl and butyl acetoacetate, lactic acid, methyl lactate, salicylic acid, ethyl salicylate, phenyl salicylate, malic acid, tartaric acid, methyl tartrate and other hydroxycarboxylic acids and esters thereof, 4-hydroxy-4-methyl-2-pentanone , 4-hydroxy-2-pentanone, 4-hydroxy-4-methyl-2-heptanone, ketoalcohols such as 4-hydroxy-2-heptanone, monoethanolamine, N, N-dimethylethanolamine, N-methyl- Monoethanolamine, diethanolamine , Amino alcohols such as triethanolamine, methylol melamine, methylol urea, methylol acrylamide, and enol active compounds such as malonic acid diethyl ester, methyl group, methylene group or carbonyl carbon of acetylacetone (2,4-pentanedione) And compounds having a group.

  A preferred ligand is acetylacetone or an acetylacetone derivative. In the present invention, the acetylacetone derivative refers to a compound having a substituent on the methyl group, methylene group or carbonyl carbon of acetylacetone. As the substituents substituted on the methyl group of acetylacetone, all are linear or branched alkyl groups having 1 to 3 carbon atoms, acyl groups, hydroxyalkyl groups, carboxyalkyl groups, alkoxy groups, alkoxyalkyl groups, and acetylacetone As a substituent for the methylene group, a carboxyl group, each of which is a linear or branched carboxyalkyl group and a hydroxyalkyl group having 1 to 3 carbon atoms, and a substituent for the carbonyl carbon of acetylacetone is a carbon number. Is an alkyl group of 1 to 3, and in this case, a hydrogen atom is added to the carbonyl oxygen to form a hydroxyl group.

  Specific examples of preferred acetylacetone derivatives include ethylcarbonylacetone, n-propylcarbonylacetone, i-propylcarbonylacetone, diacetylacetone, 1-acetyl-1-propionyl-acetylacetone, hydroxyethylcarbonylacetone, hydroxypropylcarbonylacetone, acetoacetic acid. , Acetopropionic acid, diacetacetic acid, 3,3-diacetpropionic acid, 4,4-diacetbutyric acid, carboxyethylcarbonylacetone, carboxypropylcarbonylacetone, diacetone alcohol.

  Of these, acetylacetone and diacetylacetone are particularly preferred. The complex of the above acetylacetone derivative and the above metal element is a mononuclear complex in which one to four molecules of the acetylacetone derivative are coordinated per metal element, and the coordinateable bond of the acetylacetone derivative is a coordinateable bond of the acetylacetone derivative When the number of hands is larger than the total number of hands, ligands commonly used for ordinary complexes such as water molecules, halogen ions, nitro groups, and ammonio groups may coordinate.

  Examples of preferred metal complexes include tris (acetylacetonato) aluminum complex, di (acetylacetonato) aluminum / aco complex, mono (acetylacetonato) aluminum / chloro complex, di (diacetylacetonato) aluminum complex, ethylacetate Acetate aluminum diisopropylate, aluminum tris (ethylacetoacetate), cyclic aluminum oxide isopropylate, tris (acetylacetonato) barium complex, di (acetylacetonato) titanium complex, tris (acetylacetonato) titanium complex, di-i -Propoxy bis (acetylacetonato) titanium complex salt, zirconium tris (ethyl acetoacetate), zirconium tris (benzoic acid) complex salt, etc. are mentioned. These are excellent in stability in aqueous coating solutions and in gelation promotion effect in sol-gel reaction during heat drying, and among them, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), di ( Acetylacetonato) titanium complex and zirconium tris (ethylacetoacetate) are preferred.

  Although the description of the counter salt of the metal complex described above is omitted in this specification, the type of the counter salt is arbitrary as long as it is a water-soluble salt that maintains the neutrality of the charge as the complex compound, such as nitrate, Salt forms such as halogenates, sulfates, phosphates, etc., that ensure stoichiometric neutrality are used. For the behavior of the metal complex in the silica sol-gel reaction, see J.A. Sol-Gel. Sci. and Tec. There is a detailed description in 16.209 (1999). The following scheme is estimated as the reaction mechanism. That is, in the coating solution, the metal complex has a coordinated structure and is stable, and in the dehydration condensation reaction that starts in the heat drying process after coating, it is considered that crosslinking is promoted by a mechanism similar to an acid catalyst. In any case, the use of this metal complex has led to the improvement of coating solution aging stability and film surface quality, as well as high hydrophilicity and high durability.

In addition to the above-mentioned metal complex catalyst, a catalyst that promotes hydrolysis and polycondensation of a metal alkoxide compound selected from Si, Ti, Zr, and Al and can cause a bond with a hydrophilic polymer is used in combination. May be. Examples of such a catalyst include hydrogen halides such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, carboxylic acids such as formic acid and acetic acid, and the structural formula represented by RCOOH. Compounds having an acidity such as substituted carboxylic acids in which R is substituted with other elements or substituents, sulfonic acids such as benzenesulfonic acid, etc., or basic compounds such as ammoniacal bases such as aqueous ammonia and amines such as ethylamine and aniline Is mentioned.
The above metal complex catalyst can be easily obtained as a commercial product, and can also be obtained by a known synthesis method, for example, reaction of each metal chloride with an alcohol.
The preferable content of the catalyst is 1 to 20% by mass, more preferably 1 to 10% by mass, based on the total solid content of the hydrophilic composition.

[Antimicrobial agent]
In order to impart antibacterial, antifungal and antialgal properties to the cover of the present invention, an antibacterial agent can be contained in the hydrophilic coating solution composition. In the formation of the hydrophilic layer, it is preferable to contain a hydrophilic and water-soluble antibacterial agent. By including a hydrophilic and water-soluble antibacterial agent, a cover excellent in antibacterial, antifungal and antialgal properties can be obtained without impairing surface hydrophilicity.
As the antibacterial agent, it is preferable to add a compound that does not decrease the hydrophilicity of the cover. Examples of such an antibacterial agent include inorganic antibacterial agents and water-soluble organic antibacterial agents. As the antibacterial agent, those exhibiting a bactericidal effect against fungi existing around us, such as bacteria represented by Staphylococcus aureus and Escherichia coli, and fungi such as fungi and yeast are used.

Examples of organic antibacterial agents include phenol ether derivatives, imidazole derivatives, sulfone derivatives, N-haloalkylthio compounds, anilide derivatives, pyrrole derivatives, quaternary ammonium salts, pyridines, triazines, benzoisothiazolines, and isothiazolines. It is done.
For example, 1,2-benzisothiazolin-3-one, N-fluorodichloromethylthio-phthalimide, 2,3,5,6-tetrachloroisophthalonitrile, N-trichloromethylthio-4-cyclohexene-1,2-dicarboxyl Imido, copper 8-quinolinate, bis (tributyltin) oxide, 2- (4-thiazolyl) benzimidazole (hereinafter referred to as TBZ), methyl 2-benzimidazole carbamate (hereinafter referred to as BCM), 10,10 '-Oxybisphenoxyarsine (hereinafter referred to as OBPA) 2,3,5,6-tetrachloro-4- (methylsulfone) pyridine, bis (2-pyridylthio-1-oxide) zinc (hereinafter referred to as ZPT) >, N, N-dimethyl-N ′-(fluorodichloromethylthio) -N′-phenylsulfamide <dichloro Luanide>, poly- (hexamethylene biguanide) hydrochloride, dithio-2-2′-bis (benzmethylamide), 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, 2-bromo-2 -Nitro-1,3-propanediol, hexahydro-1,3-tris- (2-hydroxyethyl) -S-triazine, p-chloro-m-xylenol, 1,2-benzisothiazolin-3-one, etc. However, it is not limited to these.
These organic antibacterial agents can be appropriately selected and used in consideration of hydrophilicity, water resistance, sublimation property, safety and the like. Among organic antibacterial agents, 2-bromo-2-nitro-1,3-propanediol, TBZ, BCM, OBPA, and ZPT are preferable from the viewpoint of hydrophilicity, antibacterial effect, and cost.

  Examples of inorganic antibacterial agents include mercury, silver, copper, zinc, iron, lead, bismuth and the like in descending order of bactericidal action. For example, the thing which carry | supported metals and metal ions, such as silver, copper, zinc, nickel, on the silicate type | system | group support | carrier, phosphate type | system | group support, an oxide, glass, potassium titanate, an amino acid, etc. is mentioned. For example, zeolite antibacterial, calcium silicate antibacterial, zirconium phosphate antibacterial, calcium phosphate antibacterial, zinc oxide antibacterial, soluble glass antibacterial, silica gel antibacterial, activated carbon antibacterial, titanium oxide Antibacterial agent, titania antibacterial agent, organometallic antibacterial agent, ion exchanger ceramic antibacterial agent, layered phosphate-quaternary ammonium salt antibacterial agent, antibacterial stainless steel, etc. Absent.

Natural antibacterial agents include chitosan, a basic polysaccharide obtained by hydrolyzing chitin contained in crabs and shrimp shells.
In the present invention, Nikko's “trade name Holon Killer Bees Sera” made of aminometal in which a metal is compounded on both sides of an amino acid is preferable.
These are not transpirationable, easily interact with the polymer and crosslinker component of the hydrophilic layer, can be stably molecularly dispersed or solid dispersed, the antibacterial agent is easily exposed effectively on the hydrophilic layer surface, and Even if it is splashed with water, it does not elute, can maintain its effect for a long time, and does not affect the human body. Moreover, it can disperse | distribute stably with respect to a hydrophilic layer or a coating liquid, and deterioration of a hydrophilic layer or a coating liquid does not occur.
Among the antibacterial agents, silver-based inorganic antibacterial agents and water-soluble organic antibacterial agents are most preferable because of their great antibacterial effects. In particular, silver zeolite in which silver is supported on zeolite, which is a silicate carrier, antibacterial agent in which silver is supported on silica gel, 2-bromo-2-nitro-1,3-propanediol, TPN, TBZ, BCM, OBPA ZPT is preferred. Particularly preferred commercially available silver zeolite antibacterial agents include “Zeomic” by Shinagawa Fuel, “Sylwell” by Fuji Silysia Chemical, and “Bactenone” by JEOL. In addition, “Novalon” manufactured by Toa Gosei, in which silver is supported on an inorganic ion exchanger ceramic, “Atomy Ball” manufactured by Catalytic Chemical Industry, and “Sun Eyebac P” (manufactured by Sanai Oil), a triazine antibacterial agent are also preferable.

  The content of the antibacterial agent is generally 0.001 to 10% by mass, preferably 0.005 to 5% by mass, more preferably 0.01 to 3% by mass, and 0.02 to 1.5%. Mass% is particularly preferable, and 0.05 to 1 mass% is most preferable. If the content is 0.001% by mass or more, an effective antibacterial effect can be obtained. Further, if the content is 10% by mass or less, the hydrophilicity is not lowered, the aging is not deteriorated, and the antifouling property and the antifogging property are not adversely affected.

[Inorganic fine particles]
The hydrophilic layer of the present invention may contain inorganic fine particles in order to improve hydrophilicity, prevent cracking of the film, and improve film strength. As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate or a mixture thereof can be preferably mentioned.
The inorganic fine particles preferably have an average particle size of 5 nm to 10 μm, and more preferably 0.5 to 3 μm. Within the above range, it is possible to form a cover that is stably dispersed in the hydrophilic layer, sufficiently retains the film strength of the hydrophilic layer, and has high durability and excellent hydrophilicity.
Among the inorganic fine particles as described above, a colloidal silica dispersion is particularly preferable and can be easily obtained as a commercial product.
The content of the inorganic fine particles is preferably 80% by mass or less, and more preferably 50% by mass or less, based on the total solid content of the hydrophilic layer.

[Other ingredients]
The various additives that can be used in the coating liquid for forming the hydrophilic layer of the cover of the present invention as necessary are described below.
1) Surfactant You may add surfactant to the coating liquid for hydrophilic layer formation of the cover of this invention.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). No. (columns 8 to 17) and those described in JP-A Nos. 62-135826.

  By using the surfactant and the hydrophilic polymer of the present invention in combination, a higher hydrophilic surface can be formed. Although the mechanism has not been fully elucidated, this is because the hydrophilic segment in the polymer segment is a surfactant that is a low molecular weight compound that migrates to the coating surface during the drying process of the coating. It is presumed that high hydrophilicity was obtained by being attracted to the hydrophilic part. The addition amount of the surfactant is appropriately selected according to the purpose, but is preferably 0.001 to 10% by mass, and 0.01 to 5% by mass with respect to the total solid content of the hydrophilic composition. More preferably.

2) Ultraviolet Absorber In the present invention, an ultraviolet absorber can be used from the viewpoint of improving the weather resistance and durability of the cover.
Examples of the ultraviolet absorber are described in JP-A-58-185679, JP-A-61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Bezotriazole compounds, benzophenone compounds described in JP-A-46-2784, JP-A-5-194443, US Pat. No. 3,214,463, etc., JP-B-48-30492, JP-A-56-21141 Cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, Special Tables The triazine compounds described in JP-A-8-501291, Research Disclosure No. Examples thereof include compounds described in No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.
The addition amount is appropriately selected according to the purpose, but generally it is preferably 0.5 to 15% by mass in terms of solid content.

3) Antioxidant In order to improve the stability of the cover of the present invention, an antioxidant can be added to the coating solution for forming the hydrophilic layer. Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. No. 5, JP-A-54-262447, JP-A-63-113536, JP-A-63-163351, JP-A-2-262654, JP-A-2-71262, JP-A-3-121449, Examples thereof include those described in JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
Although the addition amount is appropriately selected according to the purpose, it is preferably 0.1 to 8% by mass in terms of solid content.

4) Solvent When forming the hydrophilic layer of the cover of the present invention, it is also effective to add an appropriate organic solvent to the hydrophilic layer forming coating solution in order to ensure the formation of a uniform coating film on the substrate.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.
In this case, it is effective to add in a range that does not cause a problem in relation to OC (volatile organic solvent), and the amount is preferably 0 to 50% by mass, more preferably 0 to the entire coating liquid at the time of cover formation. It is the range of -30 mass%.

5) Polymer compound Various polymer compounds can be added to the coating liquid for forming a hydrophilic layer of the cover of the present invention within the range not inhibiting the hydrophilicity in order to adjust the film physical properties of the hydrophilic layer. High molecular compounds include acrylic polymer, polyvinyl alcohol resin, polyvinyl butyral resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin, phenol resin, polycarbonate resin, polyvinyl formal resin, shellac, vinyl resin, acrylic resin. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination. Of these, vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, a copolymer containing “carboxyl group-containing monomer”, “methacrylic acid alkyl ester”, or “acrylic acid alkyl ester” as a structural unit is also preferably used as the copolymer composition of the polymer binder.

In addition to this, if necessary, for example, leveling additives, matting agents, waxes for adjusting film physical properties, tackifiers, etc. within a range that does not impair hydrophilicity in order to improve adhesion to the substrate, etc. Can be contained.
As the tackifier, specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, 5-6p (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms). An ester with an alcohol having, an ester of (meth) acrylic acid with an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer comprising an ester of (meth) acrylic acid with an aromatic alcohol having 6 to 14 carbon atoms) And a low molecular weight tackifying resin having a polymerizable unsaturated bond.

  In the antifogging cover of the present invention, the thickness of the coating (hydrophilic film) is preferably 0.1 μm to 2 μm. When the film thickness is 0.1 μm or more, a sufficient hydrophilic effect can be obtained. Further, when the thickness is 2 μm or less, defects such as drying unevenness do not occur. In general, if the coating thickness is thin, the protrusions on the surface of the member cannot be sufficiently filled, so a relatively thick coating is required.However, the present invention has high wettability with the member and is superior in leveling property of the coating liquid. Also, high hydrophilicity can be obtained with a thin film.

The antifogging cover of the present invention can be obtained by applying a hydrophilic layer forming coating solution on a substrate, heating and drying to form a surface hydrophilic layer. The heating temperature and heating time for forming the hydrophilic layer are not particularly limited as long as the solvent and the time in which the solvent in the sol solution can be removed and a strong film can be formed. It is preferably 150 ° C. or lower, and the heating time is preferably within 1 hour.
The cover of the present invention can be prepared by a known coating method, and is not particularly limited. For example, spray coating method, dip coating method, flow coating method, spin coating method, roll coating method, film applicator method, screen A printing method, a bar coater method, a brush coating, a sponge coating or the like can be applied.

  The drying temperature of the coating solution is preferably 10 ° C to 150 ° C, more preferably 25 ° C to 100 ° C. When the drying temperature is low, sufficient crosslinking reaction does not proceed and the coating strength is low. If the temperature is high, the coating film tends to crack, and the antifogging property is partially insufficient. The drying time is preferably 5 minutes to 1 hour. More preferably, it is 10 minutes to 30 minutes. If the drying time is short, the coating strength may decrease due to insufficient drying. If the drying time is excessively longer than necessary, the substrate may deteriorate.

In the present invention, the center line average roughness Ra of the surface of the hydrophilic layer is 1.0 nm to 5.0 nm. Preferably it is 1 nm-3 nm.
The Tg of the hydrophilic coating is preferably 40 ° C. to 150 ° C. from the viewpoint of coating strength. The elastic modulus of the hydrophilic coating is preferably 1 GPa to 7 GPa.
Ra indicates the centerline average roughness that can be analyzed by optical interferometry or the like.
The method for controlling the surface property of the hydrophilic layer described above controls the particle size and content of the inorganic fine particles used; adjusts the surface roughness of the substrate itself (the temperature at which the substrate itself is molded, Control of the viscosity of the coating liquid composition for forming the hydrophilic layer, the heating temperature and the speed of the hydrophilic coating, and the like. It is not limited. In addition, when an AR coat layer or a hard coat layer is formed on the surface of the substrate, it can be controlled by the particle diameter of inorganic fine particles (SiO ₂ or the like) contained in the layer. Of course, when the particle size is reduced, the surface becomes smooth.
Moreover, it can also control by the temperature and time which dry the apply | coated coating film. Smoothing can be achieved by increasing the leveling property of the coating solution.

  In the present invention, an intermediate layer may be provided between the substrate and the hydrophilic layer as necessary for the purpose of improving adhesion to the substrate. The intermediate layer is not particularly limited. Hydrophilic layers having different compositions may be provided, or a known anticorrosion layer represented by a chromate system may be provided.

  In the present invention, the hydrophilic layer has a water contact angle of 15 ° or less, preferably 10 ° or less, both before and after being immersed in water at 30 ° C. for 500 hours. Therefore, it can be said that the anti-fogging cover of the present invention has sufficient hydrophilicity and the effect can be sustained for a sufficiently long time.

The degree of hydrophilicity of the hydrophilic layer surface can also be evaluated in the measurement of surface free energy. For example, the surface free energy can be measured using the Zisman plot method. Specifically, an aqueous solution of an inorganic electrolyte such as magnesium chloride uses the property that the surface tension increases with the concentration. After measuring the contact angle in air and at room temperature using the aqueous solution, the horizontal axis indicates the surface of the aqueous solution. Take the tension, the value obtained by converting the contact angle into cos θ on the vertical axis, plot the points of aqueous solutions of various concentrations to obtain a linear relationship, and the surface tension when cos θ = 1, that is, contact angle = 0 °, It is a measurement method defined as the surface free energy of a solid. The surface tension of water is 72 mN / m, and it can be said that the higher the surface free energy value, the higher the hydrophilicity.
A hydrophilic layer whose surface free energy measured by such a method is in the range of 70 mN / m to 95 mN / m, preferably 72 mN / m to 93 mN / m, more preferably 75 mN / m to 90 mN / m is hydrophilic. Excellent performance and good performance.

〔Base material〕
Although the base material used for this invention is not specifically limited, Glass is preferable from a transparency viewpoint. A transparent resin that is lighter and easier to process than glass is also preferred. Among the transparent resins, a resin with a particularly high transparency having a light transmittance of 80% or more is preferable. In particular, it is preferable to use polymethyl methacrylate (PMMA) or polycarbonate (PC) resin. These resins may be copolymers. Moreover, you may color with various pigments and dyes as needed.
The refractive index of the substrate is preferably 1.4 to 1.9. Outside this range, the difference in refractive index of the hydrophilic layer of the present application tends to be large, and sufficient performance may not be exhibited. Preferably, the refractive index difference between the base material and the hydrophilic layer is 0.5% to 30.0%, more preferably 0.5% to 10% with respect to the hydrophilic layer. The refractive index can be measured with a refractometer (FE3000 manufactured by Otsuka Electronics).

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In addition, with a part means a mass part.

[Example 1]
400 parts of distilled water, 70 parts of ethanol, and 10 parts of a 5% by weight aqueous solution of an anionic surfactant having the following structure were added to the types and amounts of hydrophilic polymers and metal alkoxide compounds listed in Table 1 below, and the mixture was stirred at 25 ° C. for 30 minutes. A hydrophilic composition was obtained.
Next, the hydrophilic composition was applied to a concave portion of a glass meter cover (plate thickness: 2 mm, curvature radius: 400 mm) so that the thickness after drying was 1 μm, followed by drying at 100 ° C. for 10 minutes. The obtained hydrophilic treated glass was evaluated by the following method.

Evaluation method / Center line average roughness Ra
Using a digital optical profilometer (manufactured by WYKO), an area of 100 μm square was measured by a light interference method under the condition of a cut-off of 0.25 mm.
-Refractive index The refractive index of the base material and the hydrophilic layer was measured with a refractometer (FE3000 manufactured by Otsuka Electronics Co., Ltd.).
-Water immersion The substrate was immersed in tap water adjusted to 30 ° C for 500 hours and then dried at 90 ° C for 5 minutes.
-Contact angle of water The contact angle meter DropMaster500 manufactured by Kyowa Interface Science Co., Ltd. was used to determine the contact angle of water droplets on the surface of the hydrophilic layer using ultrapure water. The contact angle was evaluated before and after the water immersion.
・ Heat heat durability After leaving the obtained hydrophilic treated surface in an environment of 60 ° C. and 90% RH for 5 minutes, drying at 90 ° C. for 5 minutes is one cycle, and after 5 cycles, the contact angle of the hydrophilic surface is determined by the above method. The antifogging property was measured by the following method.
(Anti-fogging evaluation)
Water vapor at 40 ° C. was applied to the hydrophilic treated surface for 1 minute (the distance from the water vapor jet to the sample was 20 cm), and the cloudiness after separation from the water vapor was visually determined according to the following criteria.
Create and evaluate 10 samples,
Excellent: No fogging is observed in all 10 samples.
Good: 1 to 2 samples are partially or entirely clouded.
Poor: Cloudiness is observed partially or entirely on three or more samples.
The results are shown in Table 1.

[Examples 2-11, Comparative Examples 1-8]
The same procedure as in Example 1 was conducted except that the base material (thickness and radius of curvature are the same as those used in Example 1), hydrophilic polymer, metal alkoxide, and other components described in Table 1 were used. It was.

  A method for synthesizing Compound A and Compound B, which are hydrophilic polymers, is shown below. Other hydrophilic polymers can be synthesized in the same manner.

Compound A
To a three-necked flask, 100 parts of acrylamide, 10 parts of 3-mercaptopropyltrimethoxysilane, and 200 parts of dimethylacetamide were added and heated and mixed at 80 ° C. under a nitrogen stream. Subsequently, 0.1 part of 2,2′azobis (2,4dimethylvaleronitrile) was added and the reaction was carried out for 5 hours. The obtained reaction liquid was dripped in 3000 L of methanol, and the solid substance was deposited.
The solid matter was taken out by filtration and then dried at 60 ° C. for 12 hours to obtain Compound A.
The molecular weight of the obtained compound A was measured by GPC and determined from the standard polystyrene equivalent value.

Compound B
100 parts of acrylamide, 20 parts of acrylamide-propyltriethoxysilane, and 500 parts of dimethylformamide were added to a three-necked flask and mixed at 80 ° C. under a nitrogen stream.
Subsequently, 0.1 part of 2,2′azobis (2,4dimethylvaleronitrile) was added and the reaction was carried out for 5 hours. The obtained reaction solution was dropped into 3000 L of n-hexane to precipitate a solid.
The solid matter was taken out by filtration and then dried at 60 ° C. for 12 hours to obtain Compound B.
The molecular weight of the obtained compound B was measured by GPC and obtained from the standard polystyrene equivalent value.

In the table, a commercially available reagent was used as the metal alkoxide. Colloidal silica A has an average particle size of 20 nm, and colloidal silica B has an average particle size of 150 nm (both manufactured by Nissan Chemical Co., Ltd.). The AR-coated glass is a glass having a SiO ₂ coat layer.

  The above-mentioned mass average molecular weights are all based on GPC (standard polystyrene conversion) measurement.

Claims (9)

  An anti-fogging cover in which a hydrophilic composition is coated on at least one surface of a substrate. The surface of the coating layer has a contact angle with water both before and after being immersed in water at 30 ° C. for 500 hours. An anti-fogging cover characterized by being 15 ° or less and having a center line average roughness Ra of 1.0 nm to 5.0 nm.   The antifogging cover according to claim 1, wherein the contact angle with respect to water is 10 ° or less both before and after being immersed in water at 30 ° C. for 500 hours.   The anti-fogging cover according to claim 1 or 2, wherein the substrate is made of any one of glass, acrylic resin, and polycarbonate resin.   The difference between the refractive index of the coating layer and the refractive index of the base material is 0.5% to 30.0% of the refractive index of the coating layer. Anti-fogging cover.   The antifogging cover according to any one of claims 1 to 4, wherein the hydrophilic composition contains a polymer having an alkoxysilyl group in the molecule. 6. The antifogging cover according to claim 5, wherein the polymer having an alkoxysilyl group in the molecule has a structure represented by the following general formula (II).

In the general formula (II), R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group, X represents a group represented by the following general formula (a), L ² and L ³ each independently represents a single bond or a linking group, and Y represents —NHCOR, —NHCO ₂ R, —NHCONR ₂ , —CONH ₂ , —NR ₂ , —CONR ₂ , —OCONR ₂ , —COR, —OH, _{-OR, -CO 2 M, -CO 2} R, -SO 3 M, -OSO 3 M, -SO 2 R, -NHSO 2 R, -SO 2 NR 2, -PO 3 M, -OPO 3 M, - (CH ₂ CH ₂ O) _n H, — (CH ₂ CH ₂ O) _n CH ₃ or —NR ₃ Z ¹ , wherein R represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, When there are a plurality, they may be the same or different, and M is a hydrogen atom, Kill group, an alkali metal, alkaline earth metal or an onium, n represents an integer, Z ¹ represents a halogen ion.
Formula (a): —Si (R ¹⁰² ) _a (OR ¹⁰¹ ) _3-a
(In General Formula (a), R ¹⁰¹ represents a hydrogen atom or an alkyl group, R ¹⁰² represents a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group, an aryl group, and an aralkyl group, and a represents 0-2. (In the case where a plurality of R ¹⁰¹ or R ¹⁰² are present, they may be the same as or different from each other.)   The antifogging cover according to any one of claims 1 to 6, wherein the hydrophilic composition contains an alkoxide compound of any element selected from Si, Ti, Zr, and Al.   The surface of the coating layer has a contact angle with water of 5 ° or more and 15 ° or less both before and after being immersed in water at 30 ° C. for 500 hours. Antifogging cover as described in 1.   The antifogging cover in any one of Claims 1-8 is used for a meter, The cover for meters characterized by the above-mentioned.